<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <form action="https://www.baidu.com/s">
        <input type=" text" name="wd">
        <button>百度一下</button>
    </form>
    <!-- 只要表单有name属性会默认提交到地址栏中 -->
    <!-- <form action="">
        <input type="text" name="user">
        <button type="submit">提交</button>
    </form> -->
</body>

</html>